Vehicle glazings

ABSTRACT

A vehicle glazing provided with a mark indicating a security related attribute of the vehicle. In a laminated glazing the mark is preferably located within the glazing remote from the exterior of the glazing which prevents the mark being soiled and from being damaged or removed from the glazing. The mark may be formed from an ink composition that includes a phosphorescent pigment which enables it to be seen in darkness.

FIELD OF THE INVENTION

[0001] This invention relates to vehicle glazings and in particular tomarkings on vehicle glazings.

BACKGROUND OF THE INVENTION

[0002] Vehicle crime is a continuing problem for both vehicle owners andvehicle manufacturers. In the UK alone hundreds of vehicles are stoleneach day and many are broken into and have property stolen from withinthe vehicle. Furthermore, many vehicles are damaged by vandals. Vehiclemanufacturers have made attempts to reduce the risk of the theft of ordamage to vehicles by introducing a number of security features forvehicles such as sophisticated door locking systems, the provision ofintruder alarms etc. Despite the introduction of such features theactions of thieves and vandals continue to place a heavy burden onvehicle owners.

[0003] The glazings of a vehicle may be seen as weak points with respectto the security of the vehicle and when broken, for example by impact/swith a brick or pick axe handle or the like, can provide a point ofentry for thieves and/or vandals. Glazings for automotive use comprisesafety glass which may be toughened or laminated. Toughened glass is onewhich has been heated and then cooled sufficiently rapidly to createcompressive stresses at the surface, balanced by tensile stresses in thecore. When broken it shatters into fragments with blunt edges. Laminatedglass comprises a number of plies of sheet material and includes atleast one glass ply which is adhered to a plastic layer. The glass, whenstruck, cracks -but the splinters adhere to the plastic layer.

[0004] Both types of glazing provide some degree of intrusionresistance, with laminated glazings generally showing better performancethan toughened glazings. A toughened glazing usually requires only onesharp blow to break it and allow access into the interior of thevehicle. Several blows may be required to penetrate a laminated glazingand it may take 30 seconds or more of continuous blows for the glazingto be penetrated to allow access into the vehicle. Toughened glazingsare less expensive to manufacture than laminated glazings and in the UKmost vehicles have a laminated windscreen to satisfy occupant retentionrequirements, the remainder of the vehicle's glazings being toughened.Aware of this and the relative intrusion resistance properties oflaminated and toughened glazings, a person wishing to gain unlawfulaccess into a vehicle usually attacks one of the toughened glazings.

[0005] Despite the fact that laminated glazings are more expensive tomanufacture than toughened glazings, some cars are manufactured in whichall glazings are laminated and it is more difficult to gain access tosuch a vehicle through one of its glazings than it would be to a vehiclewhich includes a toughened glazing. However, when incorporated into avehicle there is no apparent difference in the appearance of toughenedand laminated glass, and so a person wishing to gain unlawful accessinto a vehicle is just as likely to attack a laminated glazing of an“all laminated” vehicle, as a toughened glazing of a conventionallyglazed vehicle. After a single sharp blow to the glazing the personwould realise which type of glazing is under attack and in view of thetime and effort required to penetrate a laminated glazing, it isbelieved that the person will be deterred from further attacking theglazing once they realise it is laminated, and possibly move on to findanother vehicle containing a toughened glazing. Provided this is thecase then access to the interior of the vehicle through the laminatedglazing will be denied, but in all likelihood the glazing will have beendamaged (for example the outer glass ply will probably be cracked) tothe extent that it requires replacement, at a cost usually borne by thevehicle owner as a direct cost for a replacement laminated glazing or anindirect cost by way of increased insurance premiums.

[0006] In view of the above mentioned problems it is desirable toprovide a vehicle glazing with means which act as a deterrent to aperson wishing to gain unlawful access into a vehicle.

BRIEF SUMMARY OF THE INVENTION

[0007] According to an aspect of the present invention there is provideda vehicle glazing comprising a plurality of plies of sheet materialbonded to one another, the glazing having two outer surfaces and aplurality of inner surfaces each being major surfaces of the plies,wherein the glazing is provided with a mark indicating a securityrelated attribute of the vehicle. Once the mark has been seen by someoneattempting to gain unlawful access to the vehicle, it is believed thatperson will be deterred from attacking and hence damaging the vehicle.

[0008] The mark may be provided between the outer surfaces of theglazing and preferably on at least one inner surface of the glazing.Applying the mark in this way avoids it being soiled and also preventsit being damaged or removed from the glazing.

[0009] The glazing may comprise a plastic layer bonded between two glassplies and the mark may be incorporated in the plastic layer of theglazing which also avoids soiling of the mark and also prevents it beingdamaged or removed from the glazing.

[0010] The mark may be applied directly to a surface of the glazing, andsuitable methods include printing, such as screen printing, pad printingor ink jet printing, or spraying (over a mask if necessary).Alternatively, it may be applied to a sticker which in turn is appliedto a surface of the glazing.

[0011] In a laminated glazing according to the invention the markpreferably indicates the glazing is laminated to serve as a deterrent todiscourage attack on the glazing from those attempting to gain unlawfulaccess to the vehicle.

[0012] When incorporated into vehicles there is no apparent differencein the appearance of toughened and laminated glass, and so someindividuals may be tempted to mark a toughened glazing to spuriouslyindicate it is laminated. Consequently it is desirable that a mark canbe applied to a laminated glazing in such a way that it is evident thatthe glazing must be laminated. This may be achieved by applying the markon to the glazing at least twice and on different surfaces, at least onebeing an inner surface. Application of the mark in this way utilises theeffect of parallax and so it is evident that the glazing is laminated.The glazing may be provided with marks that are offset from each otherand/or of different size.

[0013] According to a further aspect of the invention there is provideda vehicle glazing provided with a mark indicating a security relatedattribute of the vehicle wherein the mark is produced from a mediumincluding a luminescent, fluorescent or reflective material This aspectof the invention applies equally to laminated and toughened vehicleglazings. Vehicles that include toughened glazings have in the past beenprovided with stickers adhered to the surface of the glazing facing theinterior of the vehicle that specify a security feature of the vehicle(for example the provision of an intruder alarm or other securityfeature). However, these stickers can be difficult to see in the darkand therefore ineffective at night, a time when many vehicle crimesoccur. When the mark includes a luminescent material preferably aphosphorescent material the mark is visible in daylight and also indarkness (for example at night or in a dimly lit car park). Fluorescentor reflective materials can assist in drawing attention to the mark whenit is illuminated in darkness (for example by street lighting ortorchlight).

[0014] The medium including a luminescent, fluorescent or reflectivematerial may be applied directly to a surface of the glazing andsuitable methods include printing, such as screen printing, pad printingor ink jet printing, or spraying (over a mask if necessary), oralternatively it may be applied to a sticker which in turn is applied toa surface of the glazing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a fragmentary cross section of a laminated vehicleglazing having a mark applied on an inner surface of the glazing.

[0016]FIG. 2 is a fragmentary cross section of a laminated vehiclehaving a mark incorporated in a layer of the glazing.

[0017]FIG. 3 is a fragmentary cross section of a laminated vehicleglazing having two marks applied on different inner surfaces of theglazing.

[0018]FIG. 4 is a fragmentary cross section of a toughened vehicleglazing having a mark applied on one of its surfaces.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

[0019] In the drawings like reference numerals refer to like integers.Referring to FIG. 1, a laminated vehicle glazing generally designated 10comprises a plastic interlayer 12, such as polyvinylbutyral (PVB),bonded to glass plies 14 and 16. Each ply of the glazing has twosubstantially parallel major surfaces each of which has an areasignificantly greater than any of the other faces of the ply. Theglazing has two outer major surfaces (14 a, 16 a), hereinafter referredto as “outer surfaces”, and a number inner major surfaces (12 a, 12 b,14 b, 16 b), hereinafter referred to as “inner surfaces”, with the outersurfaces facing the interior and exterior of the vehicle respectively,and each inner surface being in contact with another inner surface ofanother component of the glazing. In the embodiment shown in FIG. 1 theglazing has outer glass surfaces 14 a and 16 a, inner glass surfaces 14b and 16 b which are in contact with inner surfaces 12 a and 12 brespectively of the plastic interlayer. Prior to lamination a mark inthe form of a logo which indicates the glazing is laminated, is appliedto the inner surface 14 b of outer ply 14 by screen printing. The inkused to print the mark 18 may be a ceramic ink or a non-ceramic ink.Ceramic inks are commonly used on vehicle glazings and are more durablethan non-ceramic inks, but a glazing printed with a ceramic ink requiresfiring at a temperature in the region of 600° C. to cause the ceramicmaterial to become fused to the glazing. However, in this embodiment theink is non-ceramic and contains a luminescent pigment, in particular aphosphorescent pigment, which has a long persistence time as hereinafterdefined. A luminescent material (and hence all phosphorescent materials)is one in which excitation energy is absorbed, stored and emitted longafter the exciting energy source has been removed.

[0020] The expression “persistence time” is used herein to refer to thetime taken for the brightness of the phosphorescent component to decayfrom its maximum value to 10% of that maximum value after the excitationsource is removed; a long persistence time is a time of one second ormore. However, while persistence times of one second are long incomparison with persistence times of certain phosphorescent pigments,such as those used in cathode ray tubes, it is preferred to use pigmentswith persistence times of several hours.

[0021] It is preferred to use LUMILUX N phosphorescent pigmentsavailable in commerce from Riedel-de Haen of Seelze, Germany. Thesepigments emit light not only during but also for a long time after thesource of excitation is removed; the emission is perceptible to adaptedeyes for between 10 and 30 hours depending on the particular pigmentemployed. A range of emission colours is available, including red, greenand yellow.

[0022] The ink for printing the mark is made up by adding a proportionof the desired LUMILUX N pigment with a clear epoxy varnish such as thatsold under the trade name POLYSCREEN, available in commerce from SericolUK Ltd, England. The ink is screen printed onto a surface of a 2.1 mmglass ply and allowed to cure, which may be at room temperature for 24hours, or for 30 to 40 minutes at 150° C. Once cured, a 0.76 mm PVBinterlayer is sandwiched between the glass ply which has been printed onand another 2.1 mm glass ply. The arrangement is such that the printedsurface of the glass ply is in contact with the PVB interlayer. Air isremoved from between the assembled plies by conventional means, and theassembly is heated in an autoclave at a pressure in the range 8×10⁵ Pato 15×10⁵ Pa (8 to 15 bar) and a temperature in the range 135 to 150° C.for a period in the range 15 to 45 minutes. The finished glazing issuitable for use as a vehicle glazing.

[0023] Suitable sources of excitation for LUMILUX N pigments are uvlight, daylight and artificial light, and the emission from the pigmentis perceptible to adapted eyes for between 10 and 30 hours depending onthe particular pigment employed. Thus, when applied to a vehicle glazingthe mark will be visible in daylight and also in darkness, for exampleat night or in a dimly lit car park, a time when many vehicle crimesoccur. Indeed, during the night light from artificial lighting, such asthat from the headlights of other passing vehicles or artificial lightsprovided in car parks, incident on the mark will increase the energyabsorbed within the pigment and hence the light emitted therefrom.

[0024] A fluorescent material (one which absorbs light of short(invisible) wavelength and emits light of longer (visible) wavelength)or a reflective material may be added to the ink composition or mayreplace the phosphorescent material in the ink composition. Thesematerials may assist in drawing attention to the mark when it isilluminated in darkness (for example by street lighting or bytorchlight).

[0025] The mark may be applied to an outer surface of the glazing andwhere this is done it is preferable to apply the mark on the surface ofthe glazing facing the interior of the vehicle where it will not besubjected to external weathering and is less likely to be damaged orremoved by vandals. However, it is preferable to apply the mark betweenthe outer surfaces of the glazing, ie to an inner surface of the glazingsuch as an inner glass surface as described with reference to FIG. 1(although the mark may equally applied on the inner surface of a plasticlayer of the glazing), or to incorporate it into a layer of the laminateas shown in FIG. 2. In FIG. 2 a section of plastic interlayer 12 hasbeen cut out and a substrate 19 which includes a representation of themark is inserted into the cut out section. Application of the mark on aninner surface or within a layer of the laminate avoids soiling of themark and also prevents it from being damaged or removed from theglazing.

[0026] In this particular embodiment the mark printed on the glazing isin the form of a logo to indicate the glazing is laminated, however,other forms of mark may be applied to the glazing to indicate othersecurity features of the vehicle.

[0027] It will be appreciated that suitable methods of applying the markdirectly to a surface of the glazing may be used and include screenprinting, pad printing, ink jet printing or spraying (over a mask ifnecessary). Alternatively the mark may be applied to a sticker which isthen adhered to a surface of the glazing by a suitable adhesive.

[0028] The mark may be applied to laminated vehicle glazings, inparticular curved glazings, which commonly comprise two glass pliesbonded by a plastic layer. The glass ply facing the exterior of thevehicle normally has a thickness of 1.5 mm or more to provide improvedresistance to stone chipping. The glass ply (or plies) of such alaminate may be semi-toughened which is especially desirable when thelaminate is to be used for opening sidelights in vehicle doors which arerequired to withstand slamming of the door with the window unsupportedon at least one edge. A laminated vehicle glazing may alternativelycomprise a single glass ply bonded to a plastic layer or it may comprisea combination of multiple glass plies and multiple plastic layers bondedto one another.

[0029] The mark is usually applied to the glazing only once but it maybe applied more than once. FIG. 3 shows a glazing in which a mark hasbeen applied twice. In addition to mark 18 which has been printed onsurface 14 b, a further mark 18′ is applied on surface 16 b in such away that the two marks 18 and 18′ are slightly offset from each other.Applying the mark in this manner utilises the effect of parallax andwould indicate to a person looking at the glazing that the mark has beenapplied to more than one surface of the plies and hence it would beevident that the glazing comprises more than one ply (ie it islaminated). This manner of representation of the mark would also servesas a deterrent to discourage attack on the glazing from those attemptingto gain unlawful access to the vehicle.

[0030] When a non ceramic ink is applied to a glass ply of a laminatedglazing which is curved and/or toughened (including beingsemi-toughened), the glass ply or plies are bent and/or toughened priorto application of the mark. This avoids heat damage to the ink which maybe caused during the bending process. However, when a ceramic ink isused the mark is applied prior to bending and/or toughening of the glassply or plies and the heat required to bend and/or toughen the ply orplies also causes the ceramic material to become fused to the glass ply.

[0031] It will be appreciated that laminated vehicle glazings includeplastic layers other than PVB. Polycarbonate, acrylic and polyurethaneare some examples.

[0032] Referring to FIG. 4, a toughened vehicle glazing 20 has a mark 18applied to one of its outer surfaces. The mark indicates an attribute ofthe vehicle relating to the security if the vehicle. The ink used toprint the mark may be a ceramic ink or a non-ceramic ink that contains aluminescent material (in particular a phosphorescent material), afluorescent material and/or a reflective material each of which aids inthe mark being visible in darkness. As previously described light fromartificial lighting, such as that from the headlights of other passingvehicles or artificial lights provided in car parks, incident on themark will increase the energy absorbed within the phosphorescent pigmentand hence the light emitted therefrom. The fluorescent and/or reflectivematerials may also assist in drawing attention to the mark when it isilluminated in darkness (for example by street lighting or bytorchlight). In a preferred embodiment the ink is non ceramic andcontains a phosphorescent pigment as hereinbefore described. Preferablythe mark is applied to the surface of the glazing facing the interior ofthe vehicle where it will not be subjected to external weathering and isless likely to be damaged or removed by vandals.

[0033] The toughened glazing may or may not be curved and when a nonceramic ink is used, the mark is applied after the toughening process(and bending process where appropriate) to avoid heat damage to the inkwhich may be caused during the toughening/bending process. However, whena ceramic ink is used the mark is applied prior to thetoughening/bending process and the heat required to toughen/bend theglass also causes the ceramic material to become fused to the glass.

[0034] It will be appreciated that when applying a mark to a either atoughened or a laminated vehicle glazing, suitable methods of applyingthe ink directly to a surface of the glazing may be used and includescreen printing, pad printing, ink jet printing or spraying (over a maskif necessary). Alternatively the mark may be applied to a sticker whichis then adhered to a surface of the glazing by a suitable adhesive.

What we claim is:
 1. A method for indicating that a vehicle glazing is alaminated vehicle glazing comprising: producing a laminated vehicleglazing comprised of a plurality of plies including at least two glassplies and a plastic interlayer positioned between and bonded to the twoglass plies, the laminated vehicle glazing having two outer surfaces anda plurality of inner surfaces formed by facing surfaces of the glassplies and the plastic interlayer; producing a toughened vehicle glazing;providing at least one of the plurality of plies with means forindicating to an observer of the laminated vehicle glazing that thelaminated vehicle glazing is laminated and thereby visually distinguishthe laminated vehicle glazing from the toughened vehicle glazing; andnot providing said means to the toughened vehicle glazing to therebyvisually distinguish the toughened vehicle glazing from the laminatedvehicle glazing.
 2. The method according to claim 1, wherein theproviding at least one of the plurality of plies with means forindicating to an observer of the laminated vehicle glazing that thelaminated vehicle glazing is laminated involves applying first andsecond marks to different ones of the outer and the inner surfaces sothat the first and second marks are offset from one another in a mannerwhich produces a parallax effect.
 3. The method according to claim 1,wherein the providing at least one of the plurality of plies with meansfor indicating to an observer of the laminated vehicle glazing that thelaminated vehicle glazing is laminated involves applying the means toone of the inner surfaces of the laminated vehicle glazing.
 4. Themethod according to claim 1, wherein the means provided on at least oneof the plurality of plies includes an ink containing a luminescentpigment.
 5. The method according to claim 1, wherein the means providedon at least one of the plurality of plies includes an ink containing aphosphorescent pigment.
 6. The method according to claim 1, wherein themeans provided on at least one of the plurality of plies includes an inkcontaining fluorescent material.
 7. The method according to claim 1,wherein the means provided on at least one of the plurality of pliesincludes an ink containing reflective material.
 8. A method forproducing vehicle glazings comprising: manufacturing a plurality oflaminated vehicle glazings each comprised of a plurality of pliesincluding at least two glass plies and a plastic interlayer positionedbetween and bonded to the two glass plies; manufacturing a plurality oftoughened vehicle glazings; providing at least one of the plurality ofplies associated with each of the plurality of laminated vehicleglazings with means for indicating to an observer of the laminatedvehicle glazing that the laminated vehicle glazing is laminated tothereby visually distinguish the plurality of laminated vehicle glazingfrom the plurality of toughened vehicle glazings; and not applying saidmeans to any of the plurality of toughened vehicle glazings so that theplurality of toughened vehicle glazings are visually distinguished fromthe plurality of laminated vehicle glazings.
 9. The method according toclaim 8, wherein the providing at least one of the plurality of pliesassociated with each of the plurality of laminated vehicle glazings withmeans for indicating to an observer of the laminated vehicle glazingthat the laminated vehicle glazing is laminated involves applying firstand second marks to different surfaces of the plurality of plies so thatthe first and second marks are offset from one another in a manner whichproduces a parallax effect.
 10. The method according to claim 8, whereinthe providing at least one of the plurality of plies associated witheach of the plurality of laminated vehicle glazings with means forindicating to an observer of the laminated vehicle glazing that thelaminated vehicle glazing is laminated involves applying the means to asurface of one of the plies that faces another one of the plies.
 11. Themethod according to claim 8, wherein the means provided on at least oneof the plurality of plies includes an ink containing a luminescentpigment.
 12. The method according to claim 8, wherein the means providedon at least one of the plurality of plies includes an ink containing aphosphorescent pigment.
 13. The method according to claim 8, wherein themeans provided on at least one of the plurality of plies includes an inkcontaining fluorescent material.
 14. The method according to claim 8,wherein the means provided on at least one of the plurality of pliesincludes an ink containing reflective material.
 15. A method forproducing vehicle glazings comprising: manufacturing a plurality ofvehicle glazings; providing those of said vehicle glazings that arelaminated vehicle glazings, each comprised of a plurality of pliesincluding at least two glass plies and a plastic interlayer positionedbetween and bonded to the two glass plies, with visual indicating meansfor visually indicating to an observer that those of said vehicleglazings are laminated vehicle glazings and thereby visually distinguishsaid laminated vehicle glazings from other vehicle glazings that are notlaminated vehicle glazings.
 16. The method according to claim 15,including not providing said visual indicating means to any of thevehicle glazings that are not laminated vehicle glazings.
 17. The methodaccording to claim 15, wherein the providing of the visual indicatingmeans involves applying first and second marks to different surfaces ofthe plurality of plies so that the first and second marks are offsetfrom one another in a manner which produces a parallax effect.
 18. Themethod according to claim 15, wherein the providing of the visualindicating means involves applying the visual indicating means to asurface of one of the plies that faces another one of the plies.
 19. Themethod according to claim 15, wherein the visual indicating meansincludes an ink containing a luminescent pigment.
 20. The methodaccording to claim 15, wherein the visual indicating means includes anink containing a phosphorescent pigment.
 21. The method according toclaim 15, wherein the visual indicating means includes an ink containingfluorescent material.
 22. The method according to claim 15, wherein thevisual indicating means includes an ink containing reflective material.23. Use of a visual indicating means on a laminated vehicle glazing tovisually distinguish the laminated vehicle glazing from other vehicleglazings that are not laminated vehicle glazings comprising: providingvehicle glazings that are laminated vehicle glazings, each comprised ofa plurality of plies including at least two glass plies and a plasticinterlayer positioned between and bonded to the two glass plies, withvisual indicating means for visually indicating to an observer that saidvehicle glazings are laminated vehicle glazings, and not providing saidvisual indicating means to any vehicle glazings that are not laminatedvehicle glazings to thereby visually distinguish said laminated vehicleglazings from said vehicle glazings that are not laminated vehicleglazings.
 24. The use method according to claim 23, wherein theproviding of the visual indicating means involves applying first andsecond marks to different surfaces of the plurality of plies so that thefirst and second marks are offset from one another in a manner whichproduces a parallax effect.
 25. The method according to claim 23,wherein the providing of the visual indicating means involves applyingthe visual indicating means to a surface of one of the plies that facesanother one of the plies.
 26. The method according to claim 23, whereinthe visual indicating means includes an ink containing a luminescentpigment.
 27. The method according to claim 23, wherein the visualindicating means includes an ink containing a phosphorescent pigment.28. The method according to claim 23, wherein the visual indicatingmeans includes an ink containing fluorescent material.
 29. The methodaccording to claim 23, wherein the visual indicating means includes anink containing reflective material.